Refrigerating apparatus



Nov. 29, 1966 J. J. O'CONNELL ETAL 3,287,933

REFRIGERATING APPARATUS Original Filed Feb. 10, 1964 4 SheetsSheet 4 m mA M W Tw WW mm i A m m FL B m M NM. W OM m J The/r Affomey United StatesPatent Ofiice 3,287,933 Patented Nov. 29, 1966 3,287,933 REFRIGERATINGAPPARATUS John J. OConnell and Leonard J. Mann, Dayton, Ohio, assignorsto General Motors Corporation, Detroit, Mich., a corporation of DelawareOriginal application Feb. 10, 1964, Ser. No. 343,736, now Patent No.3,252,292 dated May 24, 1966. Divided and this application Sept. 13,1965, Ser. No. 486,647

6 Claims. (Cl. 62-441) This application is a division of our copendingapplication Serial No. 343,736, filed February 10, 1964 now Patent No.3,252,292.

This invention pertains to refrigerating apparatus and more particularlyto a refrigerator having below and above freezing compartmentsseparately cooled by separate air circuits cooled by a singleevaporator.

The growing popularity of frost free refrigerator compartments makes itdesirable to market a greater variety of sizes of refrigerators havingthis and other desirable features. It is therefore an object of thisinvention to provide a large capacity, compact, economical, low costrefrigerator which is inexpensive to manufacture and maintain, havingthe desired below and above freezing temperatures in separatecompartments which will not accumulate frost in any of the storagecompartments.

It is another object of this invention to provide a compact, removablerefrigerating system and a convenient in expensive arrangement includinga removable wall section of minimum size for readily installing andremoving such a system in a foam insulated refrigerator cabinet.

It is another object of this invention to provide an improved compact,eflicient air circulating system for a twocompartment refrigeratorcabinet.

It is another object of this invention to provide a simple singlecompact evaporator in a two-compartment refrigerator which minimizes theobstruction to air flow due to frost accumulation on the evaporatorsurfaces.

It is another object of this invention to provide a well arrangement ina foam insulated refrigerator cabinet by which the thermosensitiveelement of the control system may be readily inserted and located in thedesired place and readily removed whenever desired.

It is another object of this invention to provide an improvedarrangement for defrosting an evaporator and environmental parts subjectto frosting.

These and other objects are attained in the form shown in the drawingsin which the lower below freezing cornpartment is provided with a raisedrear portion over the compressor and condenser above which there ismounted a single vertically finned evaporator having widely spaced finsat one end and closely spaced fins for the remainder thereof. Aninsulated vertical partition wall separates the evaporator from thebelow freezing compartment immediately in front of it. The belowfreezing compartment is cooled by air which is drawn under the bottom ofthe partition wall and upwardly through the closely finned portion ofthe evaporator and discharged back into the compartment by a propellertype fan located in an aperture in the partition wall. The rearinsulated wall of the below freezing compartment is provided with anopening normally closed by a narrow removable section which is slightlyhigher than the height of the evaporator and slightly wider than thethickness thereof. The compressor and condenser mounted beneath theraised portion are connected by supply and return conduits which extendthrough the opening in the rear wall and connect to the opposite end ofthe evaporator through two looped portions located at the opposite endsof the evaporator. This arrangement provides sufficient flexibility inthe connections that the evaporator can be readily inserted through thisopening and mounted at the back of the below freezing compartment. Itmay likewise be readily removed along with the removal of thecompressor, and the condenser for examination and repair in the event ofany failure.

A duct extends diagonally upwardly from the zone immediately above thewidely spaced fin portion and has a first discharge outlet behind themeat-keeping container in the lower right side, and a second dischargeoutlet in the top central portion of the above freezing compartment. Onthe lower left side of the above freezing compartment is a centrifugalfan which discharges through an expanding duct diagonally downward to adischarge outlet located behind the lower portion of the widely spacedfinned evaporator portion. A switch mounted in the top portion of theabove freezing compartment has a thermosensitive element extendingdownwardly through a well or tube in the foam insulation extending tothe top of the below freezing compartment so as to make the switchresponsive to the temperature of the air at the top of the belowfreezing compartment. The centrifugal fan located in the lower left partof the above freezing compartment is cycled in response to thetemperature of the adjustable thermostatic switch mounted in the topportion of the above freezing compartment, and having a thermosensitiveelement located above the second discharge outlet so as to be responsiveto the temperature of the above freezing compartment. A timerperiodically defrosts both sections of the evaporator through aserpentine electric heater lodged in the fins of the evaporator having aproportionately greater portion in heat transfer relation with thewidely spaced fin portion of the evaporator which accumulates the mostfrost. The drain surfaces as well as the partition wall are Providedwith heaters energized coincidentally with the energization of thedefrost heater for melting any frost or ice accumulating on the drainsurfaces or the partition Wall. The drain is provided with a removablecover for easy cleaning and is provided with a simple removable trap inthe machinery compartment.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred embodiment of the present invention isclearly shown.

In the drawings:

FIGURE 1 is a front view, with the doors removed, of a 2-compartmenthousehold refrigerator embodying one form of my invention;

FIGURE 2 is an irregular vertical section taken substantially along thelines 22 of FIGURE 1;

FIGURE 3 is a fragmentary sectional view taken substantially along thelines 33 of FIGURE 1;

FIGURE 4 is an enlarged sectional View corresponding to the bottom ofFIGURE 3 showing the heaters for the drain surface and the partitionwall;

FIGURE 5 is a sectional view taken along the lines 55 of FIGURES 1 and2;

FIGURE 6 is a front view of the below freezing compartment showing thecycle evaporator in position for removal through the opening provided inthe rear wall; and

FIGURE 7 is a wiring diagram.

Referring now more articularly to FIGURES l and 2,

there is shown a foam insulated household refrigerator cabinet 20,having an upper above freezing compartment 22, and a lower belowfreezing compartment 24, beneath which is a machinery compartment 26having separating the latter compartments a low front insulated wallportion 28 and a stepped up rear wall portion 30, which is raisedsubstantially above the front portion 28 to provide adequate spacebeneath for the sealed motor compressor unit 32 and the sheet-typecondenser 34. The rear insulated wall 36, behind the below freezingcompartment 24, is provided with a narrow vertical removable portion 38covered by a metal cover 40 beneath the lower edge or sent away forrepair.

of which extends the capillary tube supply conduit 42 connecting thecondenser 34 with the single evaporator 44 and a suction conduit 46connecting the outlet of the evaporator with the suction inlet of thecompressor 32. On the left end of evaporator 44 the conduits 42 and 46are provided with a vertical loop portion 48 providing flexibility ofthe conduits 46 and 42 to permit removal of the evaporator 44 throughthe opening provided when the removable portions 38 and 40 are removed.

This removal is clearly illustrated in FIGURE 6. The entirerefrigerating system may be removed by removing the compressor 32 andthe condenser 34 through the opening in the back of the machinerycompartment 26 along with the evaporator 34, so that the refrigeratingsystem is kept intact and may be removed for examination Therefrigerating system is readily inserted by inserting the right endthrough the opening provided by the removal of the section 38, and

passing the entire evaporator through this opening and then placing itabove the rear of the raised portion 30.

The refrigerant conduits 42 and 46 extend from the condenser 34 and thecompressor 32 through the opening at the bottom of the section 38 to thelooped portion 48 and connecting respectively to the inlet connection 50and to the top of-a vertically mounted accumulator 52 having its bottom\portion connected to the evaporator outlet 54. The evaporator 44 hashorizontal serpentine tubing provided with widely spaced vertical fins56 on the right side of the vertical partition wall 58 and a closelyfinned section 60 on the left side of the vertical partition wall 58. Aninsulated partition wall 62 is provided in front of the evaporator 44and substantially extends entirely across the rear of the below freezingcompartment 24. It includes an insulating sheet 64 which is faced with ametal sheet 66 having a bottom edge 68 turned rearwardly at an anglebeneath the lower beveled bottom portion of the insulating sheet 64.Behind the upper portion of the sheet portion 64 is provided with ahorizontal insulated structure 70 spaced above the evaporator 44 havingvertical partition wall portions 71 and 73 extending downwardly to theopposite ends of the evaporator 44 and an intermediate vertical wallportion 76 constituting a dividing means extending downwardly to thepartition wall 58. The insulating sheet 64 and the metal facing sheet 66are terminated short of the step portion 40 in front of the closelyspaced fin portion 60 to provide an air entrance 70 through which airfrom the compartment 24 enters the space beneath the closely finned part60 of the evaporator 44. A propeller-type fan 72 is rotatably mounted inan aperture 74 in the sheet 64 and the metal sheet 66 at a level higherthan the evaporator 44 between the wall portion 71 and 76 for drawingthe air from the compartment 24 beneath the bottom beveled edge 68 fordrawing the air upwardly through the closely spaced fin portion 60 anddischarging the air forwardly in the upper portion of the below freezingcompartment 24. It is driven by an electric motor 69.

A fan scroll 78 located on the lower left-hand corner of the back wallof the above freezing compartment 22,

surrounds a centrifugal fan 80 driven by an electric motor 82 fordrawing air from the above freezing compartment, and discharging the airthrough an expanding shroud 84 to a duct 86 extending through the rearwall 36 diagonally downwardly to a discharge outlet 88 in the rear wall36, behind the bottom of the widely spaced finned portion 56, of theevaporator 44. This air flows upwardly through the widely spaced finportion 56 to the air entrance 90 above the evaporator 44. The entrance90 leads to a second air duct 92 in the rear wall 36 which extendsdiagonally upwardly and has a small first air discharge opening 94discharging through the rear wall into the above freezinig compartmentdirectly behind. the meat-keeping container 96. This air discharge 94keeps the meat-keeping container at a temperature of about 30 P. whichis sufiiciently cold to keep meats for a substantial period of time andin satisfactory condition without freezing.

The second air duct 92 extends diagonally upwardly within the backwallof the cabinet to the upper centrally located discharge outlet 123located a few inches below the top wall of the refrigerator cabinet. Thefan is preferably located directly behind the high humidity container 98on the left side of the above freezing compartment 22, directly abovethe insulating wall 121 which separates the below freezing compartment22 and around the container 98 to keep this container at a suitabletemperature such as 35 F for the moist storage of fruits and vegetables.On the rear wall of the compartment 22 between the outlet 123 and thetop wall 126 there is a thermosensitive element or capillary tube whichis operably connected to the adjustable thermostatic switch 127 mountedon the right side of the discharge outlet 123. This switch 127 isconnected in series with the fan motor 82, as indicated in FIGURE 7, forthe purpose of maintaining the temperature in the compartment 22 atabout 35 F., and the temperature in the meat-keeping container 96 at atemperature of about 30 F.

On the opposite side of the upper discharge opening 123 is a secondadjustable thermostatic switch 129 which has a thermosensitive elementextending down through a tube or well 131 in the insulation of the rearwall 36 to a terminal point 133 mounted on the top wall 121 of the belowfreezing compartment 24 as shown in FIGURES 1 and 2. Thisthermosensitive element is in the form of a capillary tube having aclosed end in the portion 133 and connecting at its upper end to a fluidmotor within the switch 129. An illustration of such a switch is shownin Pat. No. 2,906,132 issued September 29, 1959.

For the purpose of defrosting the evaporator 44, there is provided aserpentine sheathed electric heater 135 having, as shown in FIGURE 6,one lower loop 137 extending across both the widely spaced fins 56 andthe closely spaced fins 60 and having two short upper loops 139extending into heat transfer relation only with the widely spaced fins56 so as to provide more heat for this portion of the evaporator since agreater amount of frost collects upon it. Upon the backside of theevaporator are provided several loops 141 of the heater 135 which extendacross both the closely spaced fins 60 and the widely spaced fins 56.For the purpose of collecting the water during defrosting, the raisedportion 30 is provided with an inclined drain trough 143 extendingdownwardly from the left to the right to a point opposite the drain 145in the rear right corner. This drain is provided with a removable cover147 for access to the drain for cleaning purposes, and for shielding thedrain from the circulating air. The drain is connected to tubing 149extending through the machinery compartment 26 to a removable diagonaldrain and seal member 151 having a normally closed end portion 153 whichnormally has a flat looped shape at the end so as to prevent flow of airtherethrough. It will, however allow the flow of water into thecollecting drain pan 155 located in the front part of the machinerycompartment 26 where it is in the flow of air which is circulated by thecondenser fan 157 driven by the fan motor 159. The drain 143 is providedwith a drain heater 161 in the form of a loop extending along the bottomhaving a second portion 163 (see FIGURE 7) extending to the drain 145,and having a third portion 165 extending laterally between the bottomedge 68 of the sheet metal face 66 and the beveled bottom edge of theinsulating sheet 64 of the dividing wall 62.

As illustrated in FIGURE 7, a timer motor 167 is connected across thesuply conductors L-1 and L-2 and at intervals of once or twice a dayoperates the dual switches 169 and 171 from the position shown in FIGURE7 to a position in which the switch 171 is opened and the switch 169 isclosed. When the switch 171 is opened, the fan motors 76, 72, and 159,as well as the motor compressor unit 32, are deenergized. The closing ofthe switch 169 energizes the defrost heater 135 including the portions137, 139, and 141. Connected in parallel with the defrost heater are thetwo portions of the drain heater 134 and 163, and the heater 165 uponthe bottom of the member 66. The drain heaters insure that any ice inthe drainage system will be melted before the defrost water melted fromthe evaporator 44 reaches the different parts of the draining system.The heater 165 assures that any frost or ice collecting upon thepartition wall 62 will be melted during the defrost period. The fanmotors 78 and 82 may also be stopped whenever the doors 173 and 175 areopened through the opening of the switches 177 and 179 which areoperated respectively by the doors 173 and 175.

The motor compressor unit along with the fan 157 and its motor 159 andthe condenser 34 may be removed through the rear opening of themachinery compartment 26. The evaporator 44 may be removed by removingthe section 38 of insulation and the cover 40 and withdrawing theevaporator through the opening provided by this removal as illustratedin FIGURE 6 by moving the left end of the evaporator 44 first throughthe opening and then withdrawing the remainder through the opening unitlit is free of the cabinets. The refrigerating system is capable ofmaintaining the compartment 24 at temperatures between 6 and 12 F.Normal operation is F. While the above freezing compartment 22 iscapable of maintaining a temperature of about 35 F. therein, with theexecption of the meat-keeping container which is maintained at about 30F. The timer motor 167 provides defrost periods once or twice a dayautomatically without any attention. The foam insulation is suffiicentlyefiicient that only thin insulated walls are required. The use of asingle finned evaporator to cool both compartments makes the cost ofmanufacture relatively low, while the arrangement of completely separateair circulating systems between the two compartments and the twosections of the evaporator provide desirable temperature and humidityconditions in both compartments at a relatively low cost. The use of thediagonal duct arrangements makes the arrangement compact and minimizesthe thickness required for the rear wall.

While the embodiment of the present invention as herein disclosed,constitutes a preferred form, it is to be understood that other formsmight be adopted.

What is claimed is as follows:

1. A refrigerator including insulating means enclosing a below freezingcompartment and an above freezing compartment, said insulating meansincluding insulated side walls and an insulated rear wall for said belowfreezing compartment, a refrigerant evaporating means in the form of asingle elongated unit located within said below freezing compartment infront of and generally parallel to said rear wall and having itsopposite ends adjacent said side walls, a partition wall located in saidbelow freezing compartment in front of said evaporating means, upwardlyextending dividing means behind and transverse to said partition wallcooperating with said evaporating means and the walls of said belowfreezing compartment to provide separate chambers on opposite sidesthereof containing the opposite ends of said evaporating means, saidpartition wall on one side of said dividing means being provided with anopening at the bottom and the top and on the opposite side of saiddividing means being imperforate, said insulating means being providedwith supply and return air passages connecting said above freezingcompartment with said separate chamber behind the imperforate portion ofsaid partition wall on the opposite side of said dividing means.

2. A refrigerator including insulating means enclosing a below freezingcompartment and an above freezing compartment, refrigerating apparatusfor cooling said oompartments, a well in the form of tubing extendingfrom said above freezing compartment to said below freezing compartment,a thermostatic control connected in controlling relation with saidrefrigerating apparatus for controlling the operation of said apparatus,said thermostatic control being located in said above freezingcompartment, said thermostatic control having a thermosensitive tubularmeans extending through said Well from said above freezing compartmentinto heat transfer relation with said below freezing compartment.

3. A refrigerator including insulating means enclosing a lower belowfreezing compartment and an upper above freezing compartment,refrigerant evaporating means located adjacent the rear wall of saidbelow freezing compartment, a meat keeper container located adjacent onelower corner of said above freezing compartment, first air duct meansenclosing an end of said evaporating means beneath said meat keepercontainer and extending upwardly therefrom behind the meat keepercontainer and behind said above freezing compartment to an upper centralzone of said above freezing compartment, said first air duct meanshaving a first discharge outlet opening into said above freezingcompartment behind said meat keeper container and having a seconddischarge outlet opening into the upper central zone of said abovefreezing compartment, a second air duct means having an inlet adjacentthe lower corner of said above freezing compartment opposite said meatkeeper container and extending diagonally therefrom behind said belowfreezing compartment to said end of said evaporating means beneath saidmeat keeper container, the opposite end of said evaporating means beinglocated in heat transfer relation with said below freezing compartment,and means for circulating air from said above freezing compartmentthrough said second air duct means into heat transfer relation with saidend of said evaporating means below said meat keeper container andthence through said second air duct means for discharge through saidfirst and second discharge outlets.

4. A refrigerator including insulating means enclosing a below freezingcompartment and an above freezing compartment, said insulating meanscomprising an insulated rear wall for said below freezing compartment,refrigerant evaporating means in the form of a single unit :having endslocated adjacent the rear wall of said below freezing compartment, meansassociated with said insulating means forming an enclosure for said evaporating means adjacent and cooperating with said rear wall, upwardlyextending dividing means extending transversely to said rear wall withinsaid enclosure and cooperating with said evaporating means to divide theinterior of said enclosure into first and second sub-compartments withthe first subcompartment containing one end of said evaporating meansand with the second subcompartment containing the opposite end of saidevaporating means, first air duct means extending from said secondsubcompartment to the upper portion of said above freezing compartment,said above freezing compartment at its lower portion having an inlet,second air duct means connecting said inlet with only said secondsubcompartment, fan means in one of said air duct means for circulatingair through said duct means between said above freezing compartment andsaid second subcompartment in heat transfer with only said opposite endof said evaporating means, and means providing air fiow between saidbelow freezing subcompartment and said first subcompartment andincluding circulating means for circulating air from said below freezingcompartment into heat transfer with only said one end of saidevaporating means.

5. A refrigerator including insulating means enclosing a below freezingcompartment and an above freezing compartment, said insulating meanscomprising an insulated rear wall for said below freezing compartment,refrigerant evaporating means in the form of a single unit having endslocated adjacent the rear wall of said below freezing compartment, oneend of said evaporating means being provided with a plurality of widelyspaced heat transfer fins, the opposite end of said evaporating meansbeing provided with a plurality of closely spaced heat transfer fins,

means associated with said insulating means forming an enclosure forsaid evaporating means adjacent and cooperating with said rear wall,upwardly extending dividing means extending transversely to said rearWall within said enclosure and cooperating with said evaporating meansat a location substantially between said Widely spaced and closelyspaced heat, transfer fins to divide the interior of said enclosure intofirst and second subcompartments with the first subcompartmentcontaining the end of the evaporating means with the closely spaced finsand with the second sumcompartment containing the end of the evaporatingmeans with the widely spaced fins, first means for circulating air fromsaid below freezing compartment through and exclusively with said firstsubcompartment and in heat transfer relation exclusively with the oneend of the evaporating means having the closely spaced fins andreturning the air to said below freezing compartment, and second meansfor circulating air from the above freezing compartment exclusively withthe second subcompar trnent and in heat transfer relation exclusivelywith the other end of the evaporating means having widely spaced finsand for returning said air to said above freezing compartment.

6. A refrigerator including insulating means enclosing a below freezingcompartment and an above freezing compartment, said insulating meansincluding insulated side walls and an insulated rear wall for said belowfreezing compartment, a refrigerant evaporating means located withinsaid below freezing compartment in front of said rear wall, a partitionwall located in said below freezing compartment in front of saidevaporating means, insulating material spaced above and extending oversaid evaporating means having downwardly extending dividing meanssubstantially parallel to said side walls behind said partition wallcooperating with and extending down to the top of said evaporating meansto provide separate chambers on opposite sides thereof, said partitionwall on one side of said dividing means being provided with an openingat the bottom and the top and on the opposite side of said dividingmeans being imperforate, said insulating means being provided withsupply and return air passages connecting said above freezingcompartment with said separate chamber behind the imperforate portion ofsaid partition wall on the opposite side of said dividing means.

References Cited by the Examiner UNITED STATES PATENTS 2,485,630 10/1949Munters.

2,576,665 11/1951 Bixl-er.

2,613,065 10/1952 Didier 16S--151 X 2,959,025 11/1960 Morrison 6240S X3,004,401 10/1961 Mann et al 624l9 X 3,151,472 10/1964 Harle et a162-419 X LLOYD L. KING, Primary Examiner.

1. A REFRIGERATOR INCLUDING INSULATING MEANS ENCLOSING A BELOW FREEZINGCOMPARTMENT AND AN ABOVE FREEZING COMPARTMENT, SAID INSULATING MEANSINCLUDING INSULATED SIDE WALLS AND AN INSULATED REAR WALL FOR SAID BELOWFREEZING COMPARTMENT, A REFRIGERANT EVAPORATING MEANS IN THE FORM OF ASINGLE ELONGATED UNIT LOCATED WITHIN SAID BELOW FREEZING COMPARTMENT INFRONT OF AND GENERALLY PARALLEL TO SAID RER WALL AND HAVING ITS OPPOSITEENDS ADJACENT SAID SIDE WALLS, A PARTITION WALL LOCATED IN SAID BELOWFREEZING COMPARTMENT IN FRONT OF SAID EVAPORATING MEANS, UPWARDLYEXTENDING DIVIDING MEANS BEHIND AND TRANSVERSE TO SAID PARTITION WALLCOOPERATING WITH SAID EVAPORATING MEANS AND